In Amazon EC2 I have a setup of proxies and 1 monitor (MON). I've installed gmond in the proxies and gmetad in MON. My data source for gmetad.conf in MON look like this:

data_source "proxies" proxy1:8654 proxy2:8654 proxy3:8654

In the proxies's gmond.conf I have:

tcp_accept_channel {
port = 8654
}

Everything is working fine, when I telnet from MON to the proxies I get the XML with the right data. The problem is that the web frontend only shows one source from cluster "proxies", indeed it shows the first source I put on the list, in this case proxy1. If I change the order:

data_source "proxies" proxy2:8654 proxy3:8654 proxy1:8654

It only shows data from proxy2.

I've installed other monitoring systems in Ganglia using TCP or UDP, even through ssh tunnels but is the first time I see this behaviour. I'm not using multicast because (as far as I know) Amazon doesn't support on their network. Why is Ganglia-Web only showing one data source?

I found the answer reading this README file. The data_source directive is not working as I thought:

data_source "proxies" proxy1:8654 proxy2:8654 proxy3:8654

This line is not going to pull data from the three sources, it pulls data from the first source and the others act as redundant sources. What I need to do is send all the data from the proxies to a gmond hub and then to the gmetad server.